Pregnancy isn't stopping Sienna Miller from enjoying herself.
As she proved by turning out for Robert Pattinson's birthday party.
The Twilight star was celebrating his 26th at London's Claridges hotel with family and friends.
Sienna was invited because her partner Tom Sturridge is a pal of Rob's from their school days when they attended the private Harrodian college in Barnes, London.
The actress looked sophisticated and on trend in a grey, belted dress with a blazer and low heels.
She was also rocking a new hair do to the event, having died her blonde locks a light tinge of red.
Photo: © Rex